refactor(task-376): share audio attribution builder

1 files changed, 49 insertions, 0 deletions

diff --git a/internal/audio/attribution.go b/internal/audio/attribution.go
new file mode 100644
index 0000000..80f2bc3
--- /dev/null
+++ b/internal/audio/attribution.go
@@ -0,0 +1,49 @@
+package audio
+
+import (
+	"fmt"
+	"path/filepath"
+	"strings"
+	"time"
+)
+
+// AttributionParams describes metadata included in OpenAI TTS attribution files.
+type AttributionParams struct {
+	Word          string
+	Model         string
+	Voice         string
+	Instruction   string
+	ProcessedText string
+	Speed         float64
+	GeneratedAt   time.Time
+}
+
+// AttributionPath returns the sidecar attribution file path for a generated audio file.
+func AttributionPath(audioFile string) string {
+	return strings.TrimSuffix(audioFile, filepath.Ext(audioFile)) + "_attribution.txt"
+}
+
+// BuildOpenAIAttribution builds the attribution content for OpenAI-generated audio.
+func BuildOpenAIAttribution(params AttributionParams) string {
+	var b strings.Builder
+	b.WriteString("Audio generated by OpenAI TTS\n\n")
+	fmt.Fprintf(&b, "Bulgarian word: %s\n", params.Word)
+	fmt.Fprintf(&b, "Model: %s\n", params.Model)
+	fmt.Fprintf(&b, "Voice: %s\n", params.Voice)
+	fmt.Fprintf(&b, "Speed: %.2f\n", params.Speed)
+
+	if params.Instruction != "" {
+		fmt.Fprintf(&b, "\nVoice instructions:\n%s\n", params.Instruction)
+	}
+	if params.ProcessedText != "" {
+		fmt.Fprintf(&b, "\nProcessed text sent to TTS: %s\n", params.ProcessedText)
+	}
+
+	generatedAt := params.GeneratedAt
+	if generatedAt.IsZero() {
+		generatedAt = time.Now()
+	}
+	fmt.Fprintf(&b, "\nGenerated at: %s\n", generatedAt.Format("2006-01-02 15:04:05"))
+
+	return b.String()
+}